The Loss of Hemolytic Capacity by a Fraction of a Culture of a Hemolytic Strepto- Coccus without Change in Agglu- Tination

on variations of streptococci as regards hemolysis and other characteristics, no complete and adequately controlled observations on the agglutination, agglutinin-binding, and agglutinogenic characteristics have been made, as far as we know, to determine whether variation in function has been associated with change in the antigenic constituents of the cocci. We are reporting, therefore, comparative observations on a strain of hemolytic streptococcus which has developed a non-hemolytic fraction. The strain under consideration is one of the Dochez, Avery, and Lancefield 5 type strains, No. 32, which had been isolated from the lung at autopsy (bronchopneumonia following measles). This strain was obtained by us during the latter part of 1919 and has been maintained on blood-streaked agar. I t was used for the production of immune serum, and also as a control strain in comparative observations on hemolysis. Thus, for more than a year it was plated on pour and